Install rEFInd

Quadruple-booting would not be possible without incredible bootloaders like rEFInd.  rEFInd is a favorite of Think quadratic. because its developer (Rod Smith) is a great guy.  You should definitely thank him for his work!)

Step 1: Boot into admin-level account

• For ease, go into Finder -> Settings and check “External disks” and “CDs, DVDs, and iPods” under “Show these items on the desktop’
• Download the rEFInd CD-R image file from here
• Mount iso by double clicking it in the “Downloads” folder
• Open Terminal and type “cd ” (include the space after “cd”)
• Drag the mounted iso from the Desktop into Terminal and hit “Enter”
  • The command should read something like “cd /Volumes/rEFInd_0.14.0.2”
• In Terminal, type “sudo ./refind-install” and hit “Enter”
  • Enter your password and hit “Enter”
  • Terminal should say, “Installation has completed successfully.”
  • If it does not, it may be that SIP is still on, in which case, you’ll need to redo the Terminal command in Step 0 for T1 and T2 Macs
• Reboot to test rEFInd

There should only be one option – macOS – go ahead and select it to boot back into macOS in order to begin the Windows installation process.

Optional Step A: Reinstalling rEFInd

You can skip this step, unless you had a functioning rEFInd, but did something to break it, and reblessing it (Step 3) doesn’t work.  The fix is to simply reinstall rEFInd.

NOTE: resetting the NVRAM won’t help, so don’t bother trying, but if that’s what brought you here, go ahead and do Step 0 first, then Step 3, and this step only if it’s still not fixed..

• From off state, press the power button and immediately hold down “Option” key
  • Choose the internal “macOS” drive (typically “MacHD”) to boot into macOS
  • NOTE: IF YOU’VE ALREADY INSTALLED WINDOWS AND ARE COMING BACK HERE, NEVER SELECT THE WINDOWS OPTION FROM THIS MENU; IT COULD DESTROY YOUR PARTITION TABLE AND FORCE YOU TO START OVER
• Login, open Terminal, and type in the following commands:
  • Type “sudo mkdir /Volumes/ESP” then your password and hit “Enter”
  • Type “sudo mount -t msdos /dev/disk0s1 /Volumes/ESP” and hit “Enter”
• Open the EFI partition from the desktop
  • Copy the EFI folder to an external location
• If you deleted the rEFInd iso you originally used to install rEFInd, that’s fine, just download it again; there may be an update anyway
• Mount the rEFInd iso by double clicking it from wherever it is
• Open Terminal and type “cd ” (include the space after “cd”)
• Drag the mounted iso from the Desktop into Terminal and hit “Enter”
  • The command should read something like “cd /Volumes/rEFInd_0.14.0.2”
• In Terminal, type “sudo ./refind-install” and hit “Enter”
  • Enter your password and hit “Enter”
  • Terminal should say, “Installation has completed successfully.”
  • If it does not, it may be that SIP is still on, in which case, you’ll need to redo the Terminal command in Step 0 for T1 and T2 Macs
• Reboot to test rEFInd

If rEFInd shows up, but only macOS boots, you can try simply dragging and dropping all the folders from the “EFI” folder you set aside, EXCEPT for the “refind” folder, since it was just freshly reinstalled there.  If that doesn’t work, you may need to start this entire quad-booting process over because your partition table may just be too whacked to recover it.  Note the possible full disk recovery option as an alternative, though this would only work on non-T-chip Macs and has yet to be tested.